(18³-7³)/(18²+18*7+7²)=(18-7)*(18²+18*7+7²)/(18²+18*7+7²)=11
D=(-8/2)^2-15=16-15=1
x1=((-b/2)+VD)/a=(4+1)/1=5
x2=((-b/2)-VD)/a=(4-1)/1=3
Ответ:3;5.
5. = 11,5 * 10⁻² = 1,15 * 10⁻¹
6. = (1/а + 1/b)*1/(a+b) = (b+a)/ab * 1/(a+b) = 1/ab
<span>600*30*10*5=895
600+(30*10)-5=895
600+300-5=895
895=895</span>
11(у-4) + 10(5-3у) - 3(4-3у) = -6
11у - 44 + 50 - 30у - 12+ 9у = -6
11у - 30у+9у = -6+44-50+12
-10у = 0
у = 0